which is similar to the ratios, \(4:2:20\) , calculated by
the SP model. However, these two ratios
are very different from the measured
ratios \(\Gamma (DD):\Gamma (DD^*):\Gamma (D^*D^*)\simeq 1:17:50\)  from
the BaBar Collaboration [1]}. Notice that in these \(P\) -wave decay channels
there exist obvious interfering effects between \(\psi (4040)\)  and \(\psi (4160)\) . A coherent
partial wave analysis combining all these exclusive channels seems to be necessary for
extracting the resonance parameters for these two states.
It should be mentioned that the measured ratios cannot also be well understood in some
existing models [2]}, [3]}.
